Instruction Manual
90CA Microphone Calibration System
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Страница 1: ...Instruction Manual 90CA Microphone Calibration System LI0056 13 May 2019...
Страница 2: ...phone definition file 4 13 May 2019 Adapter Cable with Optical Isolation added Warning about uninstalling LabView Copyright Notice 2012 19 G R A S Sound Vibration A S http www gras dk Any technical do...
Страница 3: ...ce for the Assembly 17 PXI Connections for Test of Microphones Ext Pol and Prepol 19 PXI Connections for Test of Externally Polarized Microphone Sets 21 PXI Connections for Test of Prepolarized Microp...
Страница 4: ...ions 48 Step 2 Frequency Response 51 Step 3 LEMO Reference Level Test 52 Step 4 Storing Calibration Results 53 High Frequency Calibration 54 Working with the System Files and Documentation 56 Viewing...
Страница 5: ...or assembling and connecting the hardware for both the PXI and the PCI version of 90CA Assembling and Connecting the Hardware on page 17 Illustrations of which components of the 90CA to use for the di...
Страница 6: ...ents This section introduces the most commonly used terms in relation to acoustic calibration What is Acoustic Calibration Calibration means the comparison of the value indicated by a measuring instru...
Страница 7: ...ity avail able at a given location or in a given organization Its value is accepted without reference to other standards of the same quantity In many countries a body has been established to maintain...
Страница 8: ...lines to determine when calibration is needed When you receive a new instrument When a specified time period has elapsed often one year When a specified period of usage operating hours has elapsed Whe...
Страница 9: ...preamplifiers The 90CA is available in two versions a PXI based version with boards for mounting in a NI PXI Express chassis and a PCI based version with boards for use in a PC Functionality and speci...
Страница 10: ...mplifiers Calibration up to 92 kHz Note The high frequency calibration above 92 kHz requires a 33210A or 33220A Signal Generator and a 34410A Digital Multimeter These applications are described in thi...
Страница 11: ...tolerances and so on This database can easily be extended to contain the same type of details about microphones from other manufacturers Level Calibration uses the pistonphone and an insert voltage pr...
Страница 12: ...A overall functional block diagram of the 90CA has four areas as explained here The Level Calibration Equipment block covers the components needed to determine the microphone s open circuit sensitivi...
Страница 13: ...0V Preamp 15V Type 12AQ Remote Battery Power 40 10 0 50 60 Ext Lin HP AW Lin Ext Filter HP AW CCP Input Floating Output SysCheck 50 60 70 50 60 40 20 30 10 0 10 Gain in dB Fig 7 Functional block diag...
Страница 14: ...C AC Output Max 1Vrm s 800VD C AC Output On GND AC Input Overload G R A S R A0 014 PXI Cards Control Card NI6503 Calibration Software SW0002 Control Card Data Acqui sition Card Microphone Definition...
Страница 15: ...Actuator Calibration Stand AL0010 provides a convenient platform and has a fixture for holding the preamplifier securely in place as well as recesses and column for safely parking the electrostatic a...
Страница 16: ...alibration System Software for 90CA SW0002 National Instruments Sound and Vibration Analysis SW Run Time License 779875 01 SW0012 For Level Calibration Pistonphone Calibration Stand AL0017 Intelligent...
Страница 17: ...free space avail able For easy day to day use you need easy access to the Level Calibration Equipment and the Frequency Calibration Equipment The monitor mouse and keyboard should be easy to reach Af...
Страница 18: ...phone in calibration stand Electrostatic Actuator and Actuator Stand PXI Electrical Connections for Calibration of Microphones Ext Pol and Prepol NI PXI e 1071 PXI Express Chassis with Embedded Contro...
Страница 19: ...e other USB slot on the PXIe 8101 Embedded Controller 8 Connect the monitor to the DVI socket on the PXIe 8101 Embedded Controller 9 Use the control cable for the 42AP to connect it to the COM port of...
Страница 20: ...ne in calibration stand Electrostatic Actuator and Microphone Set Calibration Stand PXI Electrical Connections for Calibration of Externally Polarized Microphone Sets NI PXI e 1071 PXI Express Chassis...
Страница 21: ...n the PXIe 8101 Embedded Controller 8 Connect the monitor to the DVI socket on the PXIe 8101 Embedded Controller 9 Use the control cable for the 42AP to connect it to the COM port of the Adapter Cable...
Страница 22: ...hone in calibration stand Electrostatic Actuator and Microphone Set Calibration Stand PXI Electrical Connections for Calibration of Prepolarized Microphone Sets NI PXI e 1071 PXI Express Chassis with...
Страница 23: ...B slot on the PXIe 8101 Embedded Controller 8 Connect the Monitor to the DVI socket on the PXIe 8101 Embedded Controller 9 Use the control cable for the 42AP to connect it to the COM port of the Adapt...
Страница 24: ...trical Connections for Calibration of Microphones Ext Pol and Prepol G R A S Type xxxx Polarization and Supply Voltage Signal Switching Power G R A S Actuator Supply Type 14AA AC Output 200VDC AC Outp...
Страница 25: ...ox socket on the rear 6 Connect the keyboard to one of the USB slots on the PC 7 Connect the mouse another USB slot on the PC 8 Connect the monitor to the VGA socket on the PC 9 Use the control cable...
Страница 26: ...Stand PCI Electrical Connections for Calibration of Externally Polarized Microphone Sets Polarization and Supply Voltage Signal Switching Power G R A S Actuator Supply Type 14AA AC Output 200VDC AC Ou...
Страница 27: ...witch Box socket on the rear 6 Connect the keyboard to one of the USB slots on the PC 7 Connect the mouse another USB slot on the PC 8 Connect the monitor to the VGA socket of the PC 9 Use the control...
Страница 28: ...on Stand PCI Electrical Connections for Calibration of Prepolarized Microphone Sets Polarization and Supply Voltage Signal Switching Power G R A S Actuator Supply Type 14AA AC Output 200VDC AC Output...
Страница 29: ...6 Connect the keyboard to one of the USB slots on the PC 7 Connect the mouse to another USB slot on the PC 8 Connect the monitor to the VGA socket on the PC 9 Use the control cable for the 42AP to con...
Страница 30: ...mplifier onto the pistonphone calibration stand Edged side upwards 1 Using the cable labeled 12 or 12A in the electrical connections diagrams on the previous pages connect the preamplifier to the inpu...
Страница 31: ...n the following figure LEMO plug of preamplifier to Switch Box To Actuator Supply 14AA Socket for plug on electro static actuator Preamplifier Grub screw finger screw 3 Connect the actuator to the 800...
Страница 32: ...0 V Electrostatic Actuator Amplifier 14AA This amplifier must be set to the correct local mains power voltage Default setting is 230 V AC For information about changing the setting see the 14AA manua...
Страница 33: ...tion 26AN Preamplifier insert voltage RA0063 to Adapter microphone DUT RA0069 to Pistonphone Adapter 42AP Pistonphone AL0017 Calibration Stand Frequency Calibration RA0014 Electrostatic Actuator AL001...
Страница 34: ...alibration 26AN Preamplifier insert voltage microphone DUT RA0049 to Pistonphone Adapter 42AP Pistonphone AL0017 Calibration Stand Frequency Calibration RA0014 Electrostatic Actuator AL0010 Calibratio...
Страница 35: ...mplifier insert voltage can be used with G R A S microphones as shown microphone DUT 42AP Pistonphone AL0017 Calibration Stand Frequency Calibration RA0014 Electrostatic Actuator AL0010 Calibration St...
Страница 36: ...fier insert voltage 1 microphone DUT RA0017 Adapter RA0023 coupler replaces the standard coupler on the pistonphone See manual for 42AP 42AP Pistonphone AL0017 Calibration Stand Frequency Calibration...
Страница 37: ...table You can also ensure that your calibrations are traceable to a reference The 40AG reference microphone is part of the 90CA for exactly this purpose The following figure shows an example of a log...
Страница 38: ...ibration Start Calibration Level Calibration Frequency Calibration and Edit Test Conditions 5 The Test Conditions you enter are displayed here part 1 of Microphone Registration 6 The Test ID you enter...
Страница 39: ...is ready for calibration We recommend a daily system verification using the 40AG as reference microphone If such a verification is performed regularly you can ensure that all parts of the system are...
Страница 40: ...ation here 2 The 42AP pistonphone supplies this information automatically If the 42AP is not connected to the COM port enter the barometric pressure hPa manually e g 1005 3 Type in the temperature C e...
Страница 41: ...nition File The Additional Remarks are for any special remarks such as front cavity height and diameter of a 40AU LS2aP microphone The system includes definitions for all G R A S standard microphone t...
Страница 42: ...unt the microphone onto the preamplifier 26AG for microphones 26AN for microphones 2 Place the microphone into the pistonphone 42AP Note Make sure the microphone is inserted all the way into the coupl...
Страница 43: ...ensitivity measurement and then an insert voltage measurement to measure the open circuit sensitivity In the first step the closed circuit sensitivity measurement two curves gradually converging are d...
Страница 44: ...d the software switches off the pistonphone pistonphone LED red and starts measuring the open circuit sensitivity by the insert voltage method Note The scale C is set to 0 1 dB 6 When the signals have...
Страница 45: ...urement mode The rest is only for debugging and information about the setup 5 Then click Start Measurement The calibration system displays three curves and the upper and lower test limits for the spec...
Страница 46: ...k Save Data The data will be stored at a path defined in the Microphone Definition File To generate a calibration certificate click Print Note The 90CA does not include a printer You must install a pr...
Страница 47: ...ox to the system The following table shows which switchbox output to connect to either the system controller or the power module Switchbox Slot Connect With To Excitation Signal BNC cable AO0 on NI Ca...
Страница 48: ...ware control panel opens a smaller window also opens where you register the test conditions for the preamplifier 5 Because the 42AP pistonphone is connected and turned on the field for the barometric...
Страница 49: ...the LEMO reference level must be done before you can measure the sensitivity Load data from a previously saved data file Measure the CCP reference level must be done before you can measure the sensit...
Страница 50: ...lifier input adapter The RA0062 is a 20 pF input adapter that is used as 20 pF dummy load on the preamplifier when you shortcircuit the BNC input 3 Mount the RA0062 on the preamplifier under test For...
Страница 51: ...C cable to the BNC connector on RA0062 3 Connect the other end of the BNC cable to the system switchbox connector called To Preamp Input Adapter 4 On the main window click Frequency Calibration a new...
Страница 52: ...ode indicates whether the current level is within the test limits green means it is OK red means it is outside the limits 10 When the measurement has stabilized and the Sensitivity OK indicator is gre...
Страница 53: ...r For example the file name for a 26AC preamplifier with the serial number 123456 will be 26AC123456 txt If the file name already exists you can choose to create a new file or to overwrite the existin...
Страница 54: ...Under the I O menu add the following information Interface RS 232 Baudrate 9600 Parity None 8 Bits For more information see the 33210A 35500B manual 4 Use a BNC cable to connect the input of 34410 to...
Страница 55: ...0 180000 200000 then the Cut off Frequency must be one of these frequencies If the Cut off Frequency is set to 92 kHz then All frequencies up to 92kHz including 100 kHz in the list will be measured by...
Страница 56: ...itions of new microphones or preamplifiers to this file but you cannot remove or add parameters to the fixed set of 22 for microphones or 28 for preamplifiers These files contain pre set test paramete...
Страница 57: ...pressure P random incidence R or other O 4 The name of the Manufacturer such as G R A S Sound Vibration List the specifications 5 Sensitivity Lower Lower limit of sensitivity 6 Sensitivity Ideal Nomin...
Страница 58: ...Nominal pressure response dB normalized to the frequency stated in line 17 21 Upper Mag Upper limit for frequency response in dB 22 Lower Mag Lower limit for frequency response in dB Data in the Pream...
Страница 59: ...y to which the frequency response is normalized 24 IECP on off Indicate whether preamplifier is CCP type 25 Frequency Frequencies for which the system calibrates the microphone 26 Ideal Mag Nominal pr...
Страница 60: ...mpt for the necessary information and create a new Setup txt file Contents of Setup txt The Setup txt contains The locations of the Microphone Definition File and the Microphone Set Definition File DA...
Страница 61: ...ration Setup Enabled Select Enabled to configure the system for high frequency calibration Cut off frequency Enter the frequency where you want the system to switch to the 33210A 35500B generator and...
Страница 62: ...in the DIAdem Report mode 3 Click Print in the 90CA software program and the calibration data is transferred to the DIAdem Data Portal The 90CA provides only the data listed in the Data Portal The da...
Страница 63: ...e first page displays the frequency response the second page contains all the data Fig 17 Calibration certificate page 2 For more information about the functions of DIAdem and the syntax of the DIAdem...
Страница 64: ...ion software is installed on the computer because it is locked to the hardware in the System Controller Data Acquisition NI card Type PCI 4461 PXI 4461 Control Switch NI card Type PCI 6503 PXI 6509 Th...
Страница 65: ...g table lists the total uncertainty for each standard microphone All the uncertainties the microphone sensitivity uncertainty the calibration conditions the AC voltage uncertainty and the pistonphone...
Страница 66: ...e 90CA using the 40AG reference microphone to ensure the validity of your calibrations If you start each calibration session with a level measurement of the 40AG you can verify that the system works p...
Страница 67: ...a mix of water and a little dishwater if the microphone is very dirty How to clean the gold connector Use a very soft foam brush Use compressed air Service and Repairs All repairs are made at G R A S...
